True or False Questions: Answer the question true if mainly true, false if mainly false. Write T or F next to the item.

1. If a study finds a statistically significant association between exposure and disease, that must mean that every person who is exposed will get the disease. F

2. A survey can be reliable but still not close to the true value.

3. Bias is a random deviation of results from the truth.

4. Screening for disease is one type of primary prevention.

5. A case-control study can examine only a single outcome or a limited set of outcomes.

6. In a crossover design, participants may be switched among treatment groups.

7. Herd immunity must be at 99% to protect the group.

8. If a health policy is part of a law, we can assume that it is effective.

9. A reservoir can be human beings, animals, insects, soils, and/or plants.

10. The social environment only affects the health of people who live in developing countries.

11. Jobs that are highly demanding and where people don't have control can be harmful to their health.